PyPy gets funding from Mozilla for Python 3.5 support

Re:PyPy gets funding from Mozilla for Python 3.5 support by kbenson on Tuesday August 09, 2016 @09:30PM (#12258907)

> just checking to be sure, your example is essentially original.filter(...).map(...).sort()

Yes, a method chaining format (such as Ruby and JS, and which can be enabled with a module in Perl) does approximate the control flow I'm referring to, The only different to the feed operator in Perl 6 is that the feed works on a per-item basis, allowing the list to be lazily generated, which also means it's a closer approximation to how you would code it in a for loop, as statements are done in succession on each item.

E.g.

    my @source = 1..Inf;
    my @elevensies = ( @source ==> map { $_*11 } );
    my @odd-elevensies = ( @elevensies ==> grep *%2 );
    my @root-of-odd-elevensies = ( @odd-elevensies ==> map *.sqrt );

Although in this case the left feed operator may be clearer.

> which in python would be `sorted([... for x in original if ...], ...)`.

> I'll agree that sometimes the functional/chainable approach is nicer, but often it also isn't necessary

Well, the example I gave was simplistic and to show direction. A more complex example would require a comprehension of a comprehension, which is where I start to have real issues with the format, and which is not represented from that example, which wasn't meant to illustrate that particular problem.

[ Parent | on HN ]

Re:PyPy gets funding from Mozilla for Python 3.5 support by icebraining on Wednesday August 10, 2016 @02:06AM (#12259794)

Your example translated to Python is also lazily generated (it uses the lazy equivalent of list comprehensions, called generator expressions):

  source = count(1)
  elevensies = (x * 11 for x in source)
  odd_elevensies = (x for x in elevensies if x%2)
  root_of_odd_elevensies = (math.sqrt(x) for x in odd_elevensies)

To me, the examples seem fairly equivalent, with the exception that Python's is, in my opinion, more readable for a newbie, since it doesn't require knowing map() or grep() - just for loops and ifs.

[ Parent | on HN ]

Re:PyPy gets funding from Mozilla for Python 3.5 support by kbenson on Wednesday August 10, 2016 @03:36AM (#12260080)

I was aware of generators in python, but I wasn't aware of the lazy lest comprehensions, which is very nice.

I agree list comprehensions in the simple form are easier for a newbie to recognize, but I also like the way map and filter make you think about your actions, and think they are clearer in the less trivial cases (as I mentioned above). I say "filter" because while I am completely familiar with that terminology, I accept that it's an unneeded departure from the common terminology for that task.

[ Parent | on HN ]

Re:PyPy gets funding from Mozilla for Python 3.5 support by icebraining on Wednesday August 10, 2016 @04:16AM (#12260231)

Well, map and filter may be more clear in certain cases, but I still don't see how they are more powerful. Seems like you can do a 1-for-1 translation between the two.

[ Parent | on HN ]

Re:PyPy gets funding from Mozilla for Python 3.5 support by kbenson on Wednesday August 10, 2016 @10:19AM (#12261916)

Oh, that's because you must have missed a few comments back where I agreed with you and backed out on any claim they were strictly more powerful. ;)

[ Parent | on HN ]

Re:PyPy gets funding from Mozilla for Python 3.5 support by icebraining on Wednesday August 10, 2016 @10:48AM (#12262156)

Ah, uh, sorry ;)

[ Parent | on HN ]